Fuel pump



Feb. 28, 1933. w. H. scHULzE FUEL PUMP Filed Dec. l0, 1927 2 Sheets-Sheet 2 the fuel inflow pipe o il 3 and 4, A is the engine body casing,

Patented Feb. 28, 1,933

WILLIAM II. SCHULZE,

F CHICAGO, ILLINOIS, ASSIGNOR TO STEWART-WARNER CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF VIRGINIA FUEL PUHP Application med December l0, 1927. Serial No. 239,043.

The purpose of this invention is to provide an Vimproved construction of a pump particularly designed for furnishing fuel to an internal combustion engine. VIt consists in the elements and features of construction shown and described as indicated in the claims.

4 In the drawings i Figure 1 is a section axial with respect to the pumping element of a device embodying this invention in one form, showing the same mounted uponl the engine body.'

Figure 2 is a similar view showing the parts in different position from Figure 1.

Figure 3 is a detail section at the line 3-3 on Figure 1.

Figure 4 is a detail section at the line 4-4 on Figure 1.

Figure 5 is a view similar toFigure 1 showing the invention in modified form.

Figure 6 isa view similar toFigure 5 showing the parts in a different position from Figure 5.

Figure 7 is a detail section at the line 'TP-7 on Figure 2.

Figure 8 is a section at the line 8-8 on Figure 7.

In the construction shown in Figures 1, 2, B is the fuel iniiow plpe; Dis

c is a check valve in ening for inflow and seating against back ow from the pump chamber; d is the check valve inthe fuel discharge pipe opening for outflow and seating against backflow toward theY pump chamber. E is a diaphragm which is clamped at its margin between the main portion, b, of the pump casing andthe cap, b1, partitioning off from the total cavity of the pump casinga chamber, e, at one side of which are located the fuel inow and outflow connections with the valve, as described. F is a plunger posipump casing; C is the the fuel delivery pipe;

- tively connected to the diaphragm for movement therewith in bothI directions, connection being made by means of nuts, 10 and 20, on

the threadedend of the plunger at opposite` sides of the diaphragm with, suitablyv dished washers, 11 and 21, interposed between the nuts and the diaphragm. For guidance of 'the fork arms,

the opposite end of the plunger a slide bearing for that end is provided at in the lower side of the pump casing. For actuating the plunger, and thereby the dia hragm (in one direction only, as hereina ter explained) there is provided a lever, G, fulcrumed in the casing. having one arm, G1, extending out from the pump casing and into the engine casingfor engagement in the latter by a moving part of the engine, the engagement shown being by means of a cam, c, on a rotatin shaft of the engine, as the timer shaft, The lever arm, G1, is forked for engaging the cam at both sides, so that the lever shall be actuated positively in both directions in the rotation of the shaft, K. The other arm, G2, of the lever, G, is connected with the plunger, F, by linkage constituting means for lost niotion between the lever and the plunger. As illustrated, and desirably, the lever arm, G2,

is forked at' the end for extending past the,

plunger at both sides of the latter. A convenient method of constructing the lever, G, forked at one end for embracing the plunger, F, and forkedat the other end for spanning the cam, k, is shown consisting in making a part, 40, having one arm of the plunger-emracing fork and having both arms of the fork for spanning the cam, and providing another part, 41, having the other arm of the plunger-embracing fork and extending transversely across the fork gap at the fulcrum of the lever, as seen at 46, a spacer being interposed between the two parts in the horizontal arm of the lever, as seen at 44, -and all arts of the lever being secured together by rlvets,

a pair of links, L1, L2, with the plungerr,

the links, L?, being pivotally connected with* and the links, L2, being pivot-- ally connected to the plunger, the two links of each pair being pivoted together, as seen at 52, and the links, L1, having at the end pivoted to the links, L2, a projection, 53, which encounters the link, L2, in the relative movement of tle' two links toward position of alignment with each other when the links are ata substantial angle to each other, preferreason of the folding of the links ably somewhat greater than right angle, as seen in Figure 1, so that the links cannot come into alignment. A spring, H, is coiled about the plunger above the forked ends of the arm, G2, of the lever, L, and is stopped upon the upper side of the forked terminalof said lever arm, a cupped washer, J, `being provided for seatlng the lower end of the spring on the lever arm as seen in Figures l and 2.

Upon considering this construction it will be seen that the movement of the lever, L, in the direction for withdrawing the forked end of the lever arm, G2, from the diaphragm, E, will effect such withdrawal only after the links, L1 and L2, are moved relatively toward position of alignment to the limit determined by the projection, 53, which at said limit is encountered by the link, L2; and that in the movement of the lever arm, G2, in the op osite direction there will occur lost motion etween said lever arm and the plunger by p away from the stopped position indicated. That is, the lever is incapable of actuating the .plunger in the direction for forcing the diaphra m toward the side of the chamber, e, at whlch the connections for fuel inflow and outflow are situated; but said lever is adapted to retract the diaphragm after it has performed the amount of movement necessary for bringing the links toward the position of alignment, into the position shown in Figure 1. It will be further recognized that the spring, H, reacting between the diaphragm and the lever for relative movement of the diaphragm and lever, effects such relative movement through the lost motion range of the lost motion connection afforded by the links, L1 and L2, between the lever and the plunger, and thus supplements the action of the lever, in respect to the incapacity vof the lever for moving the diaphragm positivel in the direction for delivering fuel through the pipe, D.

In the construction shown in Figures 5, 6`

and 7 in which the engine casing is shown at Ax; the pump casing at Bx; the fuel inflow and outflow pipes respectively at Cx and D;

the check valves 1n said pipes at cx and dx, respectively, the plunger at F1, there is substituted for the lever form of actuator of the previous figures, a directly reciprocating actuator, Gx, which terminates i`n the engine at 30 for engagement and actuation by the cam, kx, on the engine shaft, Kx. In this construction the spring, Hx, coiled about the pluri er Fx, reacts ,between the diaphragm, lg

' the upper end of an actuator, G", for'the samepurpose and with the same effect as the spring,

H, in the previously described forms react between the diaphragm, E `and the lever, G. In this construction the lost motion connection between the actuator and the plunger is afforded by giving the plunger and slide and guide bearing, as seen at 70, in the adapted for limited movement without opening the chamber and partitioning the first chamber from the second; a plunger connected to said movable wall for positive movement of said wall and plunger together in both directions, and journaled at the other end in the wall of the second chamber for guidancein its reciprocation with said mov able Wall member; a lever in the second chamber fulcrumed on the wall thereof, and means for giving said lever reciprocatory movement; operating connections between the lever and the'plunger arranged for affording lost motion between the lever and the plunger, and a spring reacting between the movable wall and the lever for relative movement of said parts throu h the lost motion range of said connection etween the lever and the plunger.

2. The construction defined in claim l, thev IGT) 

